In LTE (Long Term Evolution), a mobile station UE capable of interpreting “CA band combination” is configured to transmit an information element “interFreqNeedForGaps” as “UE Capability” to a radio base station eNB, the “interFreqNeedForGaps” indicating whether or not the mobile station UE is capable of performing an Inter-frequency measurement without a gap for each “CA band combination”.
For example, when “true” is set in the information element “interFreqNeedForGaps” transmitted by the mobile station UE, and when, in CA (Carrier Aggregation) performed using a frequency band #1 of a 2 GHz band and a frequency band #21 of a 1.5 GHz band, a carrier belonging to the frequency band #1 (or the frequency band #21) is set as a PCC (Primary Component Carrier), the mobile station UE is capable of performing a measurement in the carrier belonging to the frequency band #21 (or the frequency band #1) without a gap.
For example, if the mobile station UE includes multiple radio circuits, and uses the different radio circuits for the respective frequency bands, the mobile station UE is capable of performing the inter-frequency measurement without a gap.